Deservedly famous for the vistas from its peak, Mount Diablo State Park has more to offer than an altitude rush.

(On a clear day you can see Mount Lassen, 181 miles away.) A different payoff awaits visitors to this 20,000-acre treasure near Walnut Creek, Calif., when they head for the park's northeastern corner. Although the mountain stays bone-dry much of the year, through March it can be green and aglow with wildflowers.

The 5.9-mile Falls Trail begins in grasslands dotted with buckeye trees and deciduous oaks. While making the 1,200-foot ascent you'll cross Donner Creek, flanked in wet seasons by blooming paintbrushes, California buttercups, and blue witch nightshades. As you pass feeder creeks, listen for the sound of waterfalls—up to five in an especially wet season, ranging from 20 to 100 feet tall. Completing the loop, you'll be rewarded with fine views of the mountain's 3,849-foot summit. For maps and information, visit www.mdia.org[3].